Nonlinear AVR Control Algorithm for Synchronous Generator Using OPAL-RT

The paper presents the implementation of a nonlinear Automatic Voltage Regulator (AVR) for a synchronous generator supplying a passive load. The AVR is designed using the feedback exact linearization of the synchronous machine dynamic equations fixed to the rotor reference frame and setting a Linear Quadratic Regulator (LQR) controller to adjust the machine field voltage. This algorithm was first evaluated using an OPAL-RT real-time simulator environment and then, an actual synchronous machine was included in the system using a Hardware in the Loop (HIL) approach. The system was implemented and experimentally verified on a 1.2 kVA cylindrical-rotor synchronous generator, where the proposed AVR regulates the terminal voltage with a steady-state error below of 1% for load steps of 40%.